A relatively new display system has been developed which generates images in all three physical dimensions. The system relies on the generation within a confined space, typically, a closed dome, of a volume upon which coherent light impacts to create the images. Each image is comprised of a number of light pixels (called voxals) usually generated by one or more laser beams impacting on the generated volume within the dome.
The defined volume can be created by spinning a helix shaped surface (disk) within the dome so that as the disk spins a volume is created defined by the disk surface as it moves up and down in a helical curve. Thus, at any point in time a different height of the volume is at a given physical location within the dome. A light spot can then be created by impacting a beam of coherent light with the disk at a particular point in time coinciding with the height desired for that point of light. By timing a large number of such light beams, three dimensional objects can be created within the dome and these objects then can be viewed from any position since the spinning disk (which creates the display volume) is essentially transparent to system is the subject of U.S. patent application, Ser. No. 07/409,176.
There is presently an item on the market called a linear stepper motor. Its design and operation are well known to those skilled in the art. One of the advantages of linear stepper motors is their ability to move a motor or forcer precisely along a track or platen. Linear stepper motors also allow precise determination of the location of the forcer with respect to the platen. Linear stepper motors have the property that they are precisely controllable while also allowing for positional determination.
Available linear stepper motors, however, have at least one limitation. They are only able to direct the forcer along a straight platen. Linear stepper motors are presently incapable of operating in a circular path. Thus, a need exists in the art for a linear stepper motor that can drive a body in a circular motion.